The present invention relates to eddy current separation technology. More in particular, the present invention relates to an eddy current separation apparatus for separating particles from a particle stream, wherein the separation apparatus comprises a separator drum adapted to create out of the particle stream at least a first particle fraction moving from the drum along a first trajectory and a second particle fraction moving from the drum along a second trajectory, a feeding device upstream of the separator drum for supplying particles to said separator drum, and a splitter element provided downstream of the separator drum for splitting the first particle fraction from the second particle fraction.
Eddy current separation technology is commonly known for sorting and separating metal particles from a stream of particles. By using an eddy current separation apparatus, recovering metals such as aluminium from household, industrial and incinerated waste, including inert plastics and other materials is possible. Eddy current separation technology provides for a relatively cost effective method of recovering a large part of valuable material from rubbish and waste.
Such a known eddy current separation apparatus usually comprises a conveyor to transport the stream of waste particles towards a rotating drum comprised of magnet blocks. The drum is adapted to spin with a high rotational speed, i.e. a speed higher than the transporting velocity of the conveyor, such that it produces an eddy current in the metal particles. The eddy current interacts with different metals according to their specific mass and resistivity such that a repelling force on the particle is created. If a metal is light and conductive, for instance aluminium, the particle is lifted up and ejected from the normal flow of the particle stream along a first trajectory. These ejected particles may then be separated from the non-metal particles that continue travelling along the conveyor and fall over the drum separating them from the ejected metal particles. The drum provides in combination with a conveyor transporting velocity the means for separation. The splitter element, provided downstream of the drum, guides the two separate fractions of particles moving along respective trajectories towards respective receptacles that collect the particles of the respective fractions.
When using the eddy current separator to separate metal particles from a waste stream, the splitter element is positioned and/or orientated with respect to the drum by the operator of the separator. The composition of the waste stream causes the particles to travel along a certain particle trajectory. Consequently, after observing said particle trajectory visually and also based on the intuition of the operator, the operator may determine the best position and/or orientation for the splitter element and adjust the element accordingly. In case the particles to be separated have a relatively small diameter, the different particles are more difficult to separate and the respective trajectories of the different particle fractions are closely spaced or even partly overlap. Consequently, determining the appropriate location for the splitter element based on visual observation and intuition will be difficult.
Therefore, it is an object of the present invention to provide for an improved eddy current separation apparatus. More in particular an object of the invention is to provide an eddy current separation apparatus that enables separation of particles from a waste stream in an efficient manner even if the particles to be separated have a minimal diameter.